This is what the sensor looks like...

(image borrowed from TI)

Now... that doesn't help find the buggah real easy, now does it.. haha..
it's right under all the hose work and shit on the passenger side of the vehicle.
I'm not 100%, but i'm prettty sure that you have to take off your intake (especially if it's the thick stock hosing.) in order to reach it enough to tell what's going on....

Hope I was somewhat helpful.